This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A015876 #29 Feb 10 2024 11:35:32 %S A015876 15,69,87,102,132,175,230,638,689,1127,1349,1392,2006,5170,6680,8366, %T A015876 8390,11652,11918,12128,16748,19511,19829,23318,24597,24734,25122, %U A015876 27162,28676,30730,32864,37391,37436,37901,41082,45925,47487 %N A015876 Numbers k such that sigma(k) = sigma(k+8). %H A015876 Donovan Johnson, <a href="/A015876/b015876.txt">Table of n, a(n) for n = 1..1000</a> %H A015876 A. Weingartner, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL14/Weingartner/wein3.html">On the Solutions of sigma(n) = sigma(n+k)</a>, Journal of Integer Sequences, Vol. 14 (2011), #11.5.5. %t A015876 Select[Range[50000], DivisorSigma[1, #]==DivisorSigma[1, # + 8] &] (* _Vincenzo Librandi_, Mar 10 2014 *) %o A015876 (PARI) is(n)=sigma(n)==sigma(n+8) \\ _Charles R Greathouse IV_, Mar 09 2014 %Y A015876 Cf. A002961, A007373, A015861, A015863, A015865, A015866, A015867, A015877, A015880, A015881, A015882, A015883, A181647. %K A015876 nonn %O A015876 1,1 %A A015876 _Robert G. Wilson v_